The Resolute is one of the hero factions in the game.
As it deals increased damage when you use heroes of the faction that counter your opponent, and vice versa,

The Resolute faction counters the Dynamic faction, while the Wisdom faction counters the Resolute.

You will gain the following bonus attributes for all heroes from the Resolute faction based on how many are deployed on the battlefield:
- 2 deployed Heroes:
Troops: Increase defense by 10%
Solo: Increase defense by 8%

- 3 deployed Heroes:
Troops: Increase defense by 25% and Hp by 30%
Solo: Increase defense by 14%

To learn more about them in-game:
-Go to the Hero Hall in your city.
-Tap on Hero Recruitment.
-You’ll find the faction icons at the top right of the screen; Press on it for more details